GB2180299A - Pulsejet - Google Patents

Pulsejet Download PDF

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Publication number
GB2180299A
GB2180299A GB08515594A GB8515594A GB2180299A GB 2180299 A GB2180299 A GB 2180299A GB 08515594 A GB08515594 A GB 08515594A GB 8515594 A GB8515594 A GB 8515594A GB 2180299 A GB2180299 A GB 2180299A
Authority
GB
United Kingdom
Prior art keywords
air
intake
reverse flow
tailpipe
valves
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08515594A
Other versions
GB8515594D0 (en
Inventor
Khalil Aldoss Taha
Salameh Hussein Najjar Yousef
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB08515594A priority Critical patent/GB2180299A/en
Publication of GB8515594D0 publication Critical patent/GB8515594D0/en
Publication of GB2180299A publication Critical patent/GB2180299A/en
Withdrawn legal-status Critical Current

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02KJET-PROPULSION PLANTS
    • F02K7/00Plants in which the working fluid is used in a jet only, i.e. the plants not having a turbine or other engine driving a compressor or a ducted fan; Control thereof
    • F02K7/02Plants in which the working fluid is used in a jet only, i.e. the plants not having a turbine or other engine driving a compressor or a ducted fan; Control thereof the jet being intermittent, i.e. pulse-jet
    • F02K7/06Plants in which the working fluid is used in a jet only, i.e. the plants not having a turbine or other engine driving a compressor or a ducted fan; Control thereof the jet being intermittent, i.e. pulse-jet with combustion chambers having valves
    • F02K7/067Plants in which the working fluid is used in a jet only, i.e. the plants not having a turbine or other engine driving a compressor or a ducted fan; Control thereof the jet being intermittent, i.e. pulse-jet with combustion chambers having valves having aerodynamic valves

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

A pulsejet comprises, an intake 1, a tailpipe 4 and a reverse flow duct 5. Hot gases produced by combustion in the combustion chamber 2 will be ejected partly from the tailpipe 4 and the remaining gases will pass through the reverse flow duct 5 sweeping with them some of the incoming air. These features will negate the requirement for mechanical valves and are stated to improve thrust, specific fuel consumption, speed limit, and altitude range and to reduce the jet noise. <IMAGE>

Description

SPECIFICATION A new design of pulsejets for aeronautical applications and land moving vehicles This invention relates to pulsejet engines. The inlet duct of the conventional pulsejet has a series of inlet valves that are spring loaded into the open position. When the pressure rises into the chamber the valves are forced to close and the expanding gases are then ejected through the jet pipe and propelling nozzle, thus the depression created allows the valves to open and repeat the cycle.
The major difficulty is the insufficient life of the vibrating valves which must be very light and quick acting but have great resistance to vibration fatigue. The other main drawbacks is its 400-500 mph operating speed limit and limited altitude range due to the increase in specific fuel consumption, hence it is unsuitable as an aircraft engine. It also has a loud and vibratory noise.
According to the present invention the spring-loaded valves are dispensed with and the intake is so shaped to allow the air to enter freely from the intake and a tailpipe and a reverse flow duct. During expansion the hot gases will be ejected partly from the tailpipe and the remaining gases will pass through a reverse flow duct. The latter part of the hot gases will sweep with it some of the incoming air thus increasing the thrust and reducing the jet noise.
Therefore, the intake duct will not be completely closed during the expansion process as it happens in the conventional design, hence reducing the engine form drag and consequently increasing the net thrust.
The relative importance of the air flow which reenters from the tail pipe will be less than that in the conventional design, hence its effect on the pressure within the engine and the resulting engine thrust and specific fuel consumption. This will increase the operating speed limit and the altitude range. The smooth transfer from low to high pressures within the combustion chamber is expected to reduce the noise. These improvements on the conventional design makes the new design a possible candidate for aircraft applications. The inherent features of the new design especially dispensing with the spring loaded valves and the reduced pulsating noise makes it convenient for land moving vehicles.
A specified embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows the initial suction process Figure 2 shows the ignition process Figure 3 shows the expansion and exhaust process Figure 4 shows the recycle suction process Referring to the drawing, air is drawn through the carefully designed intake 1 into the combustion chamber 2. This air is mixed with the injected fuel, and burned when the fuel-air mixture becomes ignitable using the spark plug 3 as shown in Fig. 2.
The resulting pressure rise forces part of the combustion gases to expand and be ejected rearwards through the tail-pipe 4. The other part will expand through the reverse flow duct 5 sweeping with it some of the fresh incoming air. This will increase the resulting thrust and reduce the jet noise.
A depression will be created by exhausting the gases thus allowing a new fresh charge of air to be drawn in through the carefully designed intake, tailpipe and the reverse flow duct. At this stage the engine is ready to begin another cycle.
1. A new design of pulsejets for aeronautical applications and land moving vehicles in which the spring loaded valves are dispensed with and the intake is so shaped to allow the air to enter freely from the intake and tailpipe and a reverse flow duct. Hence reducing the relative importance of the air entering from the tailpipe, thus improving the thrust and specific fuel consumption and increasing the speed limit and altitude range. This new design keeps the intake duct open without being completely closed during the expansion process. Hence reduces the engine-form drag and boosts the net thrust.
Since part of the hot gases will be ejected from the reverse flow duct, some of the incoming air will be swept with it, thus reducing the average exit temperature and consequently the jet noise.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (1)

  1. **WARNING** start of CLMS field may overlap end of DESC **.
    SPECIFICATION A new design of pulsejets for aeronautical applications and land moving vehicles This invention relates to pulsejet engines. The inlet duct of the conventional pulsejet has a series of inlet valves that are spring loaded into the open position. When the pressure rises into the chamber the valves are forced to close and the expanding gases are then ejected through the jet pipe and propelling nozzle, thus the depression created allows the valves to open and repeat the cycle.
    The major difficulty is the insufficient life of the vibrating valves which must be very light and quick acting but have great resistance to vibration fatigue. The other main drawbacks is its 400-500 mph operating speed limit and limited altitude range due to the increase in specific fuel consumption, hence it is unsuitable as an aircraft engine. It also has a loud and vibratory noise.
    According to the present invention the spring-loaded valves are dispensed with and the intake is so shaped to allow the air to enter freely from the intake and a tailpipe and a reverse flow duct. During expansion the hot gases will be ejected partly from the tailpipe and the remaining gases will pass through a reverse flow duct. The latter part of the hot gases will sweep with it some of the incoming air thus increasing the thrust and reducing the jet noise.
    Therefore, the intake duct will not be completely closed during the expansion process as it happens in the conventional design, hence reducing the engine form drag and consequently increasing the net thrust.
    The relative importance of the air flow which reenters from the tail pipe will be less than that in the conventional design, hence its effect on the pressure within the engine and the resulting engine thrust and specific fuel consumption. This will increase the operating speed limit and the altitude range. The smooth transfer from low to high pressures within the combustion chamber is expected to reduce the noise. These improvements on the conventional design makes the new design a possible candidate for aircraft applications. The inherent features of the new design especially dispensing with the spring loaded valves and the reduced pulsating noise makes it convenient for land moving vehicles.
    A specified embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows the initial suction process Figure 2 shows the ignition process Figure 3 shows the expansion and exhaust process Figure 4 shows the recycle suction process Referring to the drawing, air is drawn through the carefully designed intake 1 into the combustion chamber 2. This air is mixed with the injected fuel, and burned when the fuel-air mixture becomes ignitable using the spark plug 3 as shown in Fig. 2.
    The resulting pressure rise forces part of the combustion gases to expand and be ejected rearwards through the tail-pipe 4. The other part will expand through the reverse flow duct 5 sweeping with it some of the fresh incoming air. This will increase the resulting thrust and reduce the jet noise.
    A depression will be created by exhausting the gases thus allowing a new fresh charge of air to be drawn in through the carefully designed intake, tailpipe and the reverse flow duct. At this stage the engine is ready to begin another cycle.
    1. A new design of pulsejets for aeronautical applications and land moving vehicles in which the spring loaded valves are dispensed with and the intake is so shaped to allow the air to enter freely from the intake and tailpipe and a reverse flow duct. Hence reducing the relative importance of the air entering from the tailpipe, thus improving the thrust and specific fuel consumption and increasing the speed limit and altitude range. This new design keeps the intake duct open without being completely closed during the expansion process. Hence reduces the engine-form drag and boosts the net thrust.
    Since part of the hot gases will be ejected from the reverse flow duct, some of the incoming air will be swept with it, thus reducing the average exit temperature and consequently the jet noise.
GB08515594A 1985-06-20 1985-06-20 Pulsejet Withdrawn GB2180299A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08515594A GB2180299A (en) 1985-06-20 1985-06-20 Pulsejet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08515594A GB2180299A (en) 1985-06-20 1985-06-20 Pulsejet

Publications (2)

Publication Number Publication Date
GB8515594D0 GB8515594D0 (en) 1985-07-24
GB2180299A true GB2180299A (en) 1987-03-25

Family

ID=10581028

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08515594A Withdrawn GB2180299A (en) 1985-06-20 1985-06-20 Pulsejet

Country Status (1)

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GB (1) GB2180299A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1741916A2 (en) * 2005-06-30 2007-01-10 General Electric Company Naturally aspirated fluidic control for diverting strong pressure waves
GB2428744A (en) * 2005-07-27 2007-02-07 Boeing Co Pulsejet
GB2435906A (en) * 2005-07-27 2007-09-12 Boeing Co Linear acoustic pulse-jet
WO2007135455A1 (en) 2006-05-19 2007-11-29 Bae Systems Plc Micro pulse jet engine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107933891B (en) * 2017-12-19 2024-02-02 西北工业大学 Duct type vertical take-off and landing aircraft low-noise casing and control surface

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB754038A (en) * 1953-06-24 1956-08-01 Snecma Pulse jet unit with leak gas deflecting device
GB757496A (en) * 1951-01-04 1956-09-19 Snecma Improvements in arrangement for controlling the air-intake orifices of jet propulsion units
GB1001645A (en) * 1961-05-27 1965-08-18 Snecma Improvements in or relating to thermopropulsive jet engines of periodic combustion type
GB1202895A (en) * 1967-03-01 1970-08-19 John Alan Charles Kentfield Improvements in or relating to fluid rectifiers
US3823554A (en) * 1973-02-20 1974-07-16 J Melenric High speed valveless resonant pulse jet engine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB757496A (en) * 1951-01-04 1956-09-19 Snecma Improvements in arrangement for controlling the air-intake orifices of jet propulsion units
GB754038A (en) * 1953-06-24 1956-08-01 Snecma Pulse jet unit with leak gas deflecting device
GB1001645A (en) * 1961-05-27 1965-08-18 Snecma Improvements in or relating to thermopropulsive jet engines of periodic combustion type
GB1202895A (en) * 1967-03-01 1970-08-19 John Alan Charles Kentfield Improvements in or relating to fluid rectifiers
US3823554A (en) * 1973-02-20 1974-07-16 J Melenric High speed valveless resonant pulse jet engine

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1741916A2 (en) * 2005-06-30 2007-01-10 General Electric Company Naturally aspirated fluidic control for diverting strong pressure waves
EP1741916A3 (en) * 2005-06-30 2014-03-19 General Electric Company Naturally aspirated fluidic control for diverting strong pressure waves
GB2428744A (en) * 2005-07-27 2007-02-07 Boeing Co Pulsejet
GB2435906A (en) * 2005-07-27 2007-09-12 Boeing Co Linear acoustic pulse-jet
US7427048B2 (en) 2005-07-27 2008-09-23 The Boeing Company Linear acoustic pulsejet
GB2428744B (en) * 2005-07-27 2009-01-21 Boeing Co Acoustic pulsejet helmet
US7581383B2 (en) 2005-07-27 2009-09-01 The Boeing Company Acoustic pulsejet helmet
GB2435906B (en) * 2005-07-27 2009-12-30 Boeing Co Linear acoustic pulsejet
WO2007135455A1 (en) 2006-05-19 2007-11-29 Bae Systems Plc Micro pulse jet engine
JP2008530450A (en) * 2006-05-19 2008-08-07 ビ−エイイ− システムズ パブリック リミテッド カンパニ− Millimeter scale pulse jet engine
AU2007253069B2 (en) * 2006-05-19 2012-02-23 Bae Systems Plc Micro pulse jet engine
US8607543B2 (en) 2006-05-19 2013-12-17 Bae Systems Plc Millimetre-scale engine

Also Published As

Publication number Publication date
GB8515594D0 (en) 1985-07-24

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)